Have you tried using the ir_translate function to program the volup/down in normal mode to nulls? I'll give it a go and see what I can come up with.

Update, If you do:

Vol+=Null.N
Vol-=Null.N

in [ir_translate] you can disable the volume up/down buttons from pulling up the volume menu if menus aren't already up. You can take the .N off and disable it entirely, but it is handy for navigation..

Strike that, only the volume knob works for menus.. remote volume buttons don't do anything..